Type 2 diabetes (T2DM) is predicted to become the number one burden of disease in Australia in the next five years and preventing T2DM is a public health priority. At least 2 million Australians have pre-diabetes and at high risk of developing T2DM.  Without intervention approximately one in three will develop T2DM within 10 years. There is strong evidence that T2DM can be prevented in high risk individuals by cost effective programs of lifestyle modification, pharmacotherapy and bariatric surgery.

A number of randomized controlled trials in a number of countries and populations have demonstrated that a range of “older” hypoglycaemic agents can prevent the development of T2DM in high risk individuals. Medications used for this purpose have included sulfonylureas, metformin, glinides, acarbose, thiazolidinediones and insulin or combinations of therapies.  Study results have varied with respect to efficacy of the various agents compared with lifestyle intervention. The US Diabetes Prevention Program (US DPP) reported that lifestyle intervention more effective than metformin while the Indian study showed them to be equally effective. Long term outcomes data are emerging.  Acarbose has been associated with decreased cardiovascular events and recent data from the US DPP show improved cardiovascular profiles. Other outcomes studies which are in progress include the acarbose ACE study and the metformin GLINT study.

A point of ongoing discussion is whether pharmacotherapy modifies the disease process or simply represents earlier treatment of milder hyperglycaemia. Most studies which have reassessed individuals after ceasing medications had reported a deterioration of glucose tolerance suggesting that the disease has not been modified. Nevertheless any delay in development of T2DM is likely to be beneficial.

To date community-based diabetes prevention programs have focused on lifestyle interventions and few have incorporated pharmacotherapy. However medications may be an appropriate and effective intervention for some individuals and should be considered when individuals are unable to do the required physical activity, or if they fail to respond to the lifestyle program.